Here’s another topic of discussion. Isn’t it kind of amazing that we have four rocky planets each with extravagantly different make-up? Mercury is an iron pinball, Venus is a sulphur hellscape, Mars is a frozen carbon dioxide wasteland, and Earth is a perfect blend of everything we need. It’s almost as though we are in the perfect system to study very different planetary bodies. Take one away and we are exceedingly more likely to presume it couldn’t exist at all. Particularly Venus and Mars.

On one hand it makes me slightly spiritual, then in my brain’s two hands I scrap that useless non-sense and start to wonder, “what other planetary makeups could exist and how would they look and behave compared to our inner planets?”